Table 2.
Comparison of classification methods for estimating BSI rate and difference in adjusted rates with 10% identifier error (simulated datasets 10-12)
| Classification | N Infections |
Crude rate (95% CI) |
Standard error | % bias | Difference in adjusted rates (95% CI) | Standard error | % bias | |
|---|---|---|---|---|---|---|---|---|
|
Gold standard |
1000 |
18.24 |
0.577 |
|
5.514 |
1.214 |
|
|
|
10: Random error | ||||||||
| HW |
869 |
15.84 (14.79, 16.90) |
0.646 |
-13.1 |
4.55 (2.33, 6.76) |
1.129 |
-17.5 |
|
| PII MPD = 0.1 |
1038 |
18.94 (17.67, 20.21) |
0.646 |
3.8 |
5.32 (2.75, 7.89) |
1.313 |
-3.5 |
|
| PII MPD = 0.9 |
860 |
15.69 (14.61, 16.77) |
0.551 |
-14.0 |
4.45 (2.18, 6.72) |
1.160 |
-19.3 |
|
|
11: Non-random error; by covariate | ||||||||
| HW |
886 |
16.15 (15.09, 17.21) |
0.543 |
-11.4 |
10.93 (8.61, 13.24) |
1.183 |
98.2 |
|
| PII MPD = 0.1 |
1010 |
18.41 (17.21, 19.62) |
0.614 |
1.0 |
11.69 (9.12, 14.26) |
1.311 |
111.9 |
|
| PII MPD = 0.9 |
858 |
15.65 (14.57, 16.72) |
0.548 |
-14.2 |
11.454 (9.09, 13.82) |
1.208 |
107.7 |
|
|
12: Non-random error; by outcome | ||||||||
| HW |
364 |
6.65 (5.98, 7.32) |
0.343 |
-63.6 |
1.94 (0.53, 3.35) |
0.720 |
-64.9 |
|
| PII MPD = 0.1 |
684 |
12.48 (10.87, 14.09) |
0.822 |
-31.6 |
3.36 (0.51, 6.20) |
1.453 |
-39.1 |
|
| PII MPD = 0.9 | 217 | 3.95 (3.39, 4.51) | 0.287 | -78.3 | 1.20 (0.00, 2.39) | 0.610 | -78.3 | |